Chain driven spinning, make up and break out tongs

ABSTRACT

A tong for spinning, making up and breaking out pipe joints, in which a chain drives the rotatable pipe gripping means and the chain is driven by a rotary fluid motor for spinning a pipe, and the motor is locked to anchor the chain during final make up and initial break out of the pipe joint, the chain being actuated by pressure responsive actuator cylinders engaging runs of the chain between the pipe gripping means and the rotary motor to apply high make up and break out torque to the pipe gripping means.

United States Patent Geczy et a1.

[451 Sept. 19,1972

[ CHAIN DRIVEN SPINNING, MAKE UP AND BREAK OUT TONGS inventors: BelaGeczy, Glendale; Carl Alfred Wilms, La Habra, both of Calif.

Assignee: Byron Jackson, Inc., Long Beach,

Calif.

Filed: April 16, 1971 App1.No.: 134,554

US. Cl ..81/57.14, 8l/57.l8 Int. Cl ..B25b 17/00, B25b 21/00 Field ofSearch....8l/57.14, 57.18, 57.19, 57.21

References Cited UNITED STATES PATENTS Beeman et al ..81/57 Lundeen..81/57 2,649,283 8/1953 Lundeen ..81/57 2,650,070 8/1953 Lundeen..81/57 2,573,212 10/1951 Martois ..81/57 Primary Examiner-James L.Jones, Jr. Attorney-Donald W. Banner, William S. McCurry and John W.Butcher [57] ABSTRACT A tong for spinning, making up and breaking outpipe joints, in which a chain drives the rotatable pipe gripping meansand the chain is driven by a rotary fluid motor for spinning a pipe, andthe motor is locked to anchor the chain during final make up and initialbreak out of the pipe joint, the chain being actuated by pressureresponsive actuator cylinders engaging runs of the chain between thepipe gripping means and the rotary motor to apply high. make up andbreak out torque to the pipe gripping means.

20 Claims, 1 1 Drawing Figures as a 84 k? I l I I l ooooooooooooocooooo0 I0 0 o I o o BACKGROUND OF THE INVENTION Power tongs have beenprovided for facilitating the making up and breaking out of the threadedjoints or couplings of well pipe, such as drill pipe and easing. Suchtongs, generally, include a pipe gripping head or jaw mechanism which isactuated into gripping engagement with the pipe and then drivenrotatively to rotate the pipe engaged thereby, while the complementalpipe is held stationary, say, by a back up tong in the case of drillpipe, or by the rotary table slips in the case of well casing.

Relatively high torque must be imposed on the rotating pipe to finallymake up the tool joints in drill pipe or initially break out such tooljoints, as well as to make up tapered threaded casing couplings.However, particularly when the drill pipe is being round tripped, orpulled from the well to enable replacement of the bit and then returnedinto the well, much time is spent rotating the stand or length of drillpipe suspended in the derrick, either to initially shoulder the tooljoint parts or to disconnect the parts after initial break out. Thus, itis desirable that the tong be capable o spinning the joint in or out, inorder to save time, at a relatively high rate of speed. The use ofchange speed mechanisms to enable the high speed, low torque spinning oftool joints and the low speed, high torque make up and break out of tooljoints is expensive, and such tongs are generally quite bulky.

More recently, there has been developed a chain actuated tong in whichthe pipe gripping means are actuated by a chain which is moved by one ormore pressure operated actuator cylinders, as more particularlydisclosed in the co-pending US. Pat. application, Ser. No. 134,553,filed Apr. 16, 1971, in the name of Carl A. Wilms.

SUMMARY OF THE INVENTION The present invention provides a novel andunobvious power pipe tong drive which employs the high torque final makeup and initial break out characteristics of the tong of theabove-mentioned application in combination with a high speed rotarymotor drive for the chain to spin up and spin out joints of pipe.

More particularly, the present invention provides a power pipe tong inwhich the pipe gripping mechanism is driven by a continuous chain whichis powered by a rotary fluid motor for spinning the pipe, and the rotarymotor and motor drive to the chain are locked when the joint is to befinally made up or initially broken out, while a reciprocating pressureoperated actuator cylinder acts on the chain intermediate the grippingmechanism and the point at which the chain is locked to apply hightorque to the pipe gripping means to finally make up the joint orinitially break out a joint. Such tong apparatus is capable of applyingrelatively high torque to the pipe with a mechanically simple system,which is, therefore, comparatively inexpensive, as compared with theusual change speed gear mechanism, and the drive is rugged and requirescomparatively small space for the capabilities in pipe joint spinning,make up and break out.

This invention possesses many other advantages, and has other purposeswhich may be made more clearly apparent from a consideration of a formin which it may be embodied. This form is shown in the drawingsaccompanying and forming part of the-present specification. It will nowbe described in detail, for the purpose of illustrating the generalprinciples of the invention; but it is to be understood that suchdetailed description is not to be taken in a limiting sense, since thescope of the invention is best defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan of a power tongmade in accordance with the invention, with portions of the housingbroken away, to expose the interior structure, with the gripping jawsretracted;

FIG. 2 is a vertical section, as taken on the line 2-2 of FIG. 1;

FIG. 3 is a view corresponding to FIG. 1 but showing the gripping jawsin pipe gripping positions and the actuator means shifted to break out ajoint of pipe;

FIG. 4 is an enlarged vertical section, as taken on the line 4-4 of FIG.2, and showing a typical actuator slide construction;

FIG. 5 is a horizontal section, as taken on the line 5- 5 of FIG. 2,with parts broken away to show the reverse stop and brake means;

FIG. 6 is an enlarged fragmentary, vertical section, as taken on theline 6-6 of FIG. 5;

FIG. 7 is a fragmentary vertical section, as taken on the line 7-7 ofFIG. 6, showing the reverse stop means in a make up condition;

FIG. 8 is a view generally corresponding to FIG. 7, but showing thereverse stop means actuated to the break out condition;

FIG. 9 is a vertical section, as taken on line 9-9 of FIG. 7;

FIG. 10 is a vertical section, as taken on the line 10- 10 of FIG. 8;and

FIG. 1 l is a schematic diagram of the control and operating system forthe tong.

DESCRIPTION OF THE PREFERRED EMBODIMENT As seen in the drawings, thetong assembly comprises a body or housing H defining an opening 0 for apipe and in which is rotatably supported pipe gripping means G,including a number of circumferentially spaced gripping jaws .I, carriedby an inner, jaw-carrying ring or rotatable member 10, and actuatableradially of the assembly from retracted positions, as seen in FIG. 1, topipe gripping positions, as seen in FIG. 3, in response to rotation ofan outer rotative member or cam ring 11, by drive means including one ormore drive chains 12, a fluid pressure operated, rotary, chain driving,spinning motor M, and, depending on whether the tong is being used tomake up or break out pipe joints, break out actuator cylinder means B0and a Y make up actuator cylinder means MU, each of which actuatorcylinder means operatively engages a portion or run of the chain orchains 12 between the motor M and the outer ring 1 1, whereby extensionof the respective cylinder means will apply a pull to the respective runof the chain and eflect angular movement of the outer ring 11 in onedirection or the other, while the motor M or its chain drive shaft islocked by lock means L.

More particularly, as best seen in FIG. 2, the housing H comprises anannular body 20 to which is suitably affixed, as by fasteners 21, a topannular plate 22. Centrally of the plate 22 is a guide ring support 23,attached to the plate 22 by fasteners 24 and having a guide insert 230defining the open top of the pipe opening 0. A bottom plate 25, affixedto the body 20 by fasteners 26, combines with the body 20 and the topplate 22 to form an annular space in which the inner ring 10 and outerring 11 are concentrically disposed for rotation.

The annular body 20 supports the outer ring 11 for rotative movement onsuitable ball bearings 27. The inner ring 10 is a composite assembly,including an annular central section 28 which defines the pipe openingand has radial windows 29 through which the jaws J are radiallyreciprocable between retracted and pipe gripping positions. Formed on orotherwise provided on the central section 28 of the inner ring is anoutwardly extended flange 280, at the outer periphery of which aresuitable ball or other bearings 30 engaged with a retaining race member31 attached to the outer ring 11, as by fasteners 32. Thus, it is seenthat the outer ring 11 is revolvable within the housing body on thebearings 27 and the outer ring 11 is revolvable relative to the inner,jaw-carrying ring 10 for a purpose which will be later described.

The gripping jaws J are box-like and comprise a top wall 33, a bottomwall 34 and an inner end wall 35, the latter being adapted, ascustomary, to receive an assortment of die carriers 36 having pipegripping dies 37 removably carried thereby. Further details of the diecarriers are not germane to the present invention, and it will beunderstood that the use of die carriers of different dimensions radiallyof the pipe opening 0 enables effective use of the tong on pipe of awide range of diameters. In order to actuate the jaws J to pipe grippingpositions, from retracted positions, each jaw has a cam roller 40joumaled between the top and bottoin walls 33, 34 on a pin 41, or othersuitable support, and the outer ring 11 has a cam surface 42 whichdefines the inner periphery of the outer ring. Such as cam and roller,tong jaw-actuating means is well known, as are other jaw-actuating meansresponsive to relative rotation of the inner and outer rings of tongs.As is well known inpower tongs useful in making up and breaking out pipejoints, without requiring that the tong be rolled over top to bottom,the cam surface 42 is compound, as seen in FIG. 1, for example. This isto say that operable on the roller 40 of each jaw the cam surface 42includes a make up ramp 42M and a break out ramp 428 at opposite sidesof central portions 43, these latter portions being indented to allowfull retraction of the jaws J at the midpoint of the compound cams 42Mand 42B. The illustrated tong assembly has means for effecting positiveretraction of the jaws J, as distinguished from spring loadedretraction, in the form of an outer cam surface 44 having portions whichparallel the make up and break out ramps 42M and 42B and a cam followerpin 45 carried by each jaw and engaged with the cam surface 44.

It will now be understood that actuation of the jaws J to the pipegripping positions, from the retracted positions, is caused by relativerotation of the inner and outer rings 10 and 11, respectively, and inthe embodiment shown, such relative rotation is caused by rotation ofthe outer ring by the chain means 12 about the inner, jaw-carrying ring10, in either direction, due to the compound nature of the cam surface42.

Break means are customarily provided to initially hold the inner ring 10stationary, 'until the jaws J are locked up on a pipe or are beingretracted from engagement with the pipe. In addition, reverse stop meansare customarily provided to limit reverse relative rotation of the innerand outer rings 10 and 11 to a point at which the jaws are fullyretracted and to prevent reclosure of the jaws on the pipe, as mightotherwise be caused by continued relative rotation of the inner andouter rings, say, so that the jaw rollers 40 would travel down to makeup ramps 42M,,during retraction of the jaws 1 following for making up ofa joint, and continue on past the central depressions 43 and up thebreak out ramps 42B of the cam surface 42. Break means are herein shownat B, and reverse stop means are shown at RS, the details of both ofwhich will be hereinafter more fully described.

In order to drive the outer ring 1 1, it is provided with sprocketmeans, including a pair of vertically spaced sprocket rings 50, 50extending about the outer periphery of the outer ring 11 and affixedthereto for rotation therewith by a number of pins 51 and retainingfasteners 52. Each sprocket 50 is engaged by one of the drive chains 12,and these chains are driven by power operated means now to be described,and including the reversible fluid motor M and the make up actuatorcylinder MU and the break out actuator cylinder B0.

Included in the tong body or housing H is a base section 66 for thepower means, this base section being suitably secured to a rear portion61 of the body member 20, as by fastenings 62. A cover plate 63 isprovided for the base housing section and is secured to the latter byfasteners 64. The fluid motor M is suitably mounted on the top plate 63,as by fasteners 65 which engage in a mounting flange 66 of the topplate.

To drive the chains 12, the fluid motor M has its output shaft 67splined or otherwise drivingly connected to a sprocket drive shaft 68which is joumaled in an upper bearing 69 and a lower bearing 70, thesebearings being interposed between the sprocket shaft 68 and removablebearing caps 71 and 72 affixed to the housing by respective fasteners 73and 74.

Fixed on the sprocket shaft 68 for rotation with the latter, as by keys75, are a pair of drive spockets 76, 76 which are engaged with thechains 12 to drive the latter in response to the rotation of the motoroutput shaft 67 in'either direction. Disposed between the sprockets 76on the sprocket shaft 68 and fixed on the shaft for rotation with thelatter by the keys is a sprocket shaft locking gear 77 forming part ofthe locking means L, previously referred to, by which the chains 12 areanchored during final make up and initial break out of a pipe joint.This locking gear has teeth 78 adapted for engagement by complementalteeth 79 on the confronting end of a locking dog 80. The dog 80 isreciprocable between a retracted position and a position at which itsteeth 79 mesh with the teeth 78 of the locking gear 77, as generallyseen in FIGS. 1 and 3, respectively, ears 82, 82 formed in the base 60and having tongue and groove connections at 83, 83 with the dog 80support the latter for reciprocation, and actuator means, in theillustrated form of a pressure operated actuator cylinder 84 having anextensible rod 85 are adapted to actuate the lock dog or slide 80between its two positions. Suitable support and anchor means for theactuator cylinder 84 are shown as a yoke member 86 affixed to the ears82 by fasteners 87 and to which one end of the cylinder 84 is pivotallyconnected at 88.

It is now apparent that the fluid motor M is capable of driving thechain drive oppositely, when the lock dog 80 is retracted, to spin thegripping means G of the tong in either direction when spinning up andspinning out pipe joints. In addition, the motor drive, when locked bythe dog 80, anchors the chains 12 so that the runs of the chains betweenthe locked sprockets 78 and the outer ring 11 may be actuated by theactuator cylinder means MU and B0 to also actuate the gripping means Gthrough an arc of motion sufficient and at sufficient torque to finallymake up or initially break out a pipe joint.

As seen in FIGS. 1, 3 and 4 to best advantage, the make up actuatorcylinder means MU includes a pressure cylinder 100 which has an ear 101at one end pivotally connected or otherwise affixed by a pin 102 to thetong housing H. The cylinder 100 has a fluid connector 103 for theadmission and exhaust of pressure fluid. A piston 104 within thecylinder 100 has a rod which projects from the other end of the cylinder100 and is connected to a slide block 106 by an enlarged head 107 on therod 105, seating in the retained in a set block 108 by a retainer 109which is fastened to the slide block 106 by suitable fasteners 109a. Theslide block 106 rides slidably between a pair of parallel rails 110which are secured by fasteners 111 to supporting flanges 1 12 whichextend longitudinally within the base 60 of the housing H.

Extending vertically through the block 106 is a sprocket shaft 113having upper and lower idler sprockets 1 14 and 1 15, respectively,mounted for rotation on suitable bearings 116 and 117 which are retainedin place by keeper plates 119 and 120 affixed to the shaft ends byrespective fasteners 121 and 122. The runs of the chains 12 between thespinning motor sprockets 78 and the outer ring sprockets 50 engage theidler sprockets 114 and 115, and, upon extension and retraction of thecylinder 100 and rod 105, are extended in loops along a plane parallelto the plane of the axes of the outer ring sprockets 50 and the motorsprockets 114 and 115 to avail of the mechanical advantage, as well asto increase the total angular movement of the gripping means G for agiven actuator stroke, with resultant savings in overall size of of thetong assembly.

The break out actuator cylinder means B0 are essentially the same as themake up actuator cylinder means MU, just described. Thus, as seen inFIGS. 1 and 3, the break out actuator cylinder means BO includes apressure cylinder 130, an end ear 131 of which is connected in the caseI! by a pin 132. A fitting 133 enables the supply and exhaust ofpressure fluid to and from the cylinder 130 to cause the piston 134 toextend the rod 135 or allow retraction of the rod, as the slide block136 is moved along guide rails 140 carried on flanges 142 within thecase base 60. This slide block 136 carries a sprocket shaft on whichsprockets like the sprockets 114 and 115 are rotatably supported, onlythe upper sprocket 144 being seen in FIGS. 1 and 3.

Since the details of the idler sprocket and slide assembly of the breakout actuator cylinder means correspond to those of the make up actuatorcylinder means MU, no further specific description is believed to benecessary, except to note that the break out actuator cylinder meansacts on the runs of chains 12 between the spinning motor sprocket 78 andthe outer ring sprockets 50 to move the outer ring 11 in the oppositedirection from the direction in which the outer ring 11 is moved by themake up cylinder means MU, when pressure fluid is supplied to either themake up cylinder or the break out cylinder 130, alternately, as will belater described.

The brake means B, previously referred to, for initially holding theinner jaw carrying ring or member 10 against rotation with the outerring, in order to set the jaws J in gripping engagement with the pipe,are best seen in FIGS. 2, 5 and 6.

More particularly, the brake means B comprises a brake disc or ringmember affixed at its inner periphery by fasteners 151 to a shoulder 152on the inner ring and extending radially in a horizontal plane, andmeans for braking engagement with the opposing faces of the brake disc150, in the form of a plurality of caliper type brake units 153 suitablyspaced about and affixed by fasteners 154 to a radial flange 155 formedon the top plate 22 on the tong housing l-I.

Each brake unit 153, as best seen in FIG. 6, comprises a horizontallysplit body providing an upper cylinder section 156 having a pistonchamber 157 opening towards the upper face of the brake disc 150 and alower cylinder section 158 providing a piston chamber 159. Each of thepiston chambers 157 and 159 contains a piston 160 provided with asuitable annular seal 161, whereby the pistons are adapted to be forcedby fluid pressure admitted to the chambers 157 and 159 toward oneanother. Friction pads 162 are provided on the pistons 160 forfrictional engagement with the disc 150. Fluid under pressure isadmitted to the piston chambers 157 and 159 by means of a passage 163which communicates with both chambers and with an inlet 164 to whichfluid is supplied from a supply conduit 165. Since it is desired thatthe brake units 153 be simultaneously engaged with the disc 150 oreffectively released, the conduit 165 is connected to each of the brakeunits, and a common source supplies pressure fluid to all chambers 157and 159 of all units 153. For example, in FIG. 6, the housing flange 22is ported at 166 and a supply conduit 167 communicates with the port 166and with additional supply porting 168 in the housing H to conduit fluidfrom a source to the brake fluid conduit 165, under the control of meanswhich control the braking action, as will be later described in respectof the control system of FIG. 11.

As previously indicated, the reverse stop means RS are provided to limitrotation of the outer or cam ring 11 relative to the inner or jawcarrying ring in a reverse direction to open the jaws J after a pipejoint is made up or broken out. To accomplish this, the reverse stopmeans permits the outer ring 1 1 to rotate relative to the inner ring 10in a selected direction, clockwise for making ,up joints and counterclockwise for breaking out joints, so that cam surfaces 42M or 42B,respectively, may force the jaws J inwardly to pipe gripping posi'-tions, while the brake means B holds the jaw carrying,

inner ring 10 stationary, and thereafter the entire gripping assembly Grotates in the selected direction. The reverse stop means RS thenfunctions to prevent rotation of the outer ring 11 relative to the innerring 10 in the reverse, jaw retracting direction, past the location atwhich the jaws are fully retracted, and the cam roller 35 of the jaws Jare in the depressions 43 of the cam surface 42.

The reverse latch means RS are best seen in FIGS. 2 and 5 through 10.More particularly, the reverse stop means includes a stop member 170 inthe form of a ring concentrically mounted upon a support flange 171which is secured by fasteners 172 to the inner or jaw carrying ring anda companion stop member in the form of a ring 174 on the outer ring 11,herein shown as an upward extension of the bearing ring 31 whichprovides a race for the ball bearings 30 on which the inner and outerrings 10 and 1 1 relatively revolve.

In FIGs. 6-10, it will be seen that the stop ring 170 is verticallyshiftable and has a splined connection 175 with the flange 171 on thejaw carrying ring 10. A suitable number of coiled compression springs176 are interposed between the stop ring 170 and an opposing portion ofthe inner ring 10 to provide means for biasing or moving the stop ring170 to an upper, normal position, as seen in FIGS. 6, 7 and 9, andactuator means 177 are provided for shifting the stop ring 170downwardly to a position, as seen in FIGS. 8 and 10, the upper positionbeing the make up stop position and the lower position being the breakout stop position.

The actuator means 177 includes an angularly shiftable ring 178 disposedabove the stop ring 170. Bearing means, such as balls 179, areinterposed between the actuator ring 178 and the stop ring 170 tofacilitate rotation of the latter relative to the former, since the stopring 170 is carried by the revolvable gripping assembly G.

Double acting fluid pressure operated cylinder means, including a pairof cylinders 180, 180, FIGS. 5 and 6, are connected with the actuatorring 178 at 181 and with the housing top flange 22 at 182, so as toeffect angular movement of the actuator ring 178 in opposite directionsrelative to the housing.

Means are provided comprising a suitable number of fixed cams 183 formedon or affixed to the housing top plate 22 by fasteners 184, and acorresponding number of traveling cams 185, formed on or affixed to theactuator ring 178 by fasteners 186, whereby angular movement of theactuator ring 178 in the direction of the arrow in FIG. 8 will effectdownward movement of the stop ring 170 from the upper position of FIGS.7 and 9 to the lower position of FIGS. 8 and 10, as indicated by thearrow in FIG. 7. Obviously, movement of the actuator ring 178 from theposition of FIGS. 8 and 10 to that of FIGS. 7 and 9, allows the springs176 to return the stop ring 170 to the normal or upper position. Suchactuation will be further described hereinafler in relation to thecontrol system of FIG. 1 1.

The stop ring 170, on its outer periphery, has a pair ofcircumferentially extended stop lugs 170a, herein shown in FIG. 5 asextending substantially 60 about the ring 170 and diametrically spaced.On the end of each lug 170a facing in a counter clockwise direction is astop face or abutment 170m which, as will later appear, stops rotationof the outer ring 11 relative to the inner ring 10 when the tong isbeing used to make up joints and the jaws J are fully retracted. At theother end of each lug 170a facing in a clockwise direction, is a face orabutment 170b, which, as will later appear, stops rotation of the outerring 11 relative to the inner ring 10 when the tong is being used tobreak out joints and the jaws J are fully retracted.

The reverse stop ring or member 174 cooperates with the stop lugs 170ato limit jaw-opening relative rotation of the inner ring 10 and theouter ring 1 1, and for this purpose, the ring 174 has upper stop lugs174a and lower stop lugs 174c extending circumferentially on the innerperiphery of the ring 174 and arranged so that these lugs arealternately located about the ring 174 at opposite sides ofdiametrically spaced vertical spaces or slots 174d having an angularextent substantially the same or slightly greater than the angularextent of the respective stop lugs 170a on the stop ring 170, wherebythe lugs 170a may move vertically in the slots 174 between the upper andlower stop positions, previously referred to.

When the reverse stop actuator means is conditioned, as seen in FIGS. 5,6, 7 and 9, for making up joints with the tong, with the reverse stopring 170 in the upper position, the upper stop lugs 174a on the ring 174provide, on their ends 174: facing in a clockwise direction, abutmentscooperative with the ends 170m of the stop lugs 170a of the stop ring170 to stop counter clockwise rotation of the outer ring 1 1 relative tothe inner ring 10 at a location with the jaws retracted, but the lugs170a will pass above the lower stop lugs 174c (See FIG. 9), so that theouter ring 11 is free to rotate in a clockwise direction relative to theinner ring 10 to close the jaws on and rotatea pipe. Alternatively, whenthe stop ring 170 is actuated to the lower position of FIGS. 8 and 10,for breaking out joints with the tong, the lower stop lugs 174c on thering 174 provide on their ends l74b facing in a counter clockwisedirection abutments cooperative with the ends lb of the stop lugs a ofthe stop ring 170 to limit clockwise rotation of the outer ring 11relative to the inner ring 10 at a location at which the jaws J areretracted, but the lugs 170a will pass beneath the upper stop lugs 174a(See FIG. 10), so that the outer ring 1 1 is free to rotate in a counterclockwise direction to close the jaws J and rotate a pipe.

In the illustrated tong, three jaws J are shown and the outer ring 1 1may move through an arc of approximately 60 in either direction from ajaw retracted position to a position at which the jaws engage the pipe.Thus, the stop lugs 170a on the stop ring 170 and the stop lugs 174a and174c on the stop ring 174 are angularly spaced to provide slots 174d ofabout 60 extent and themselves extend about 60, so that in theillustrated tong, a stop lug 174a, an adjacent slot 174d and a stop lug1740, each of about 60 in extend are located on each diametricallyopposed half of the stop ring 174. Other arrangements are possibledepending on the number of jaws and the angular motion necessary toacmate the jaws. In any event, however, the reverse stop means is veryrugged and capable of withstanding heavy shock, say when the jaws areopened at high speed, and the mass of the outer ring 1 1 is great.

In the use of the tong apparatus thus far described, the motor M isoperated, in either direction, to rotate the pipe gripping means G atrelatively high speed. To effect initial engagement of the jaws J with apipe, the brake means B must be applied, to hold the inner, jaw carryingring 10 against rotation with the outer ring 11 until the gripping ofthe pipe by the jaws is sufficient to rotate the pipe, at which timeself energization of the cam roller system works to assist in thegripping action. After the pipe is gripped, high braking effort is notdesirable since the brake must be overcome by the tong motor M. Thus,the brake means B is preferably pressured to an extent determined bytorque transmitted through the gripping means to the pipe. In addition,the lock means L should be released automatically when the spinningmotor M is operated, and the lock means L should be engaged with thespinning motor locking gear 78 when the spinning motor is not operatingto lock the spinning motor shaft, and more particularly, to lock thechain sprockets 76, when either of the actuator cylinder means MU or Bis being operated.

The following is a description of the illustrative tong control systemof FIG. 1 1, whereby the tong is operated as above described.

In order to operate the system, to make up and break out joints of pipe,a conduit 300 is connected to a suitable pressure source for supplyinghydraulic pressure fluid from the source to a main motor control valveMV which has a neutral position and selective positions for controllingfluid flow to the motor M in either direction, whereby the drivesprocket 78 for the chain means 12 will be driven in a selecteddirection to drive the gripping means G correspondingly. Thus, when themain motor control valve MV is shifted to the right, as seen in FIG. 11,pressure fluid is supplied to conduit 300M to drive the motor M in amake up direction, and when the valve MV is shifted to the left,pressure fluid supplied via a conduit 300B to drive the motor M in abreak out direction, in which case the motor is subjected to full sourcepressure from conduit 300. In the make up condition of the system,however, the maximum pressure supplied to the motor M via conduit 300Mand therefore, the maximum motor torque output, or stall torque, iscontrolled by a motor torque limiting relief valve 300R connected to themake up conduit 300M by a conduit 301. The maximum pressure in theconduit 301 is adjustable by a variable regulator valve 301R which holdsthe relief valve 300R closed until the pressure acting on the regulatorvalve 301R relieves the bias pressure from the relief valve 300R.

Operating fluid pressure from conduit 300 is supplied via a conduit 302to provide pilot pressure to a sequency valve 3028 which is normallyclosed to shut off the supply of fluid pressure from a supply conduit303 to a pilot pressure conduit 304 which leads from the sequence valve3028 to a pilot operated valve 304L which controls the flow of pressurefluid from the source conduit 303 via a conduit 305 to one or the otherof the conduits 306L and 3060 by which the lock means L, previouslydescribed, are operated to lock the motor M or release the lock. Thesequence valve 3028 is controllable or adjustable by means of a variableregulator 302R which determines at what pressure in conduit 302, andhence, conduit 300, the sequence valve will open to supply pilotpressure to the lock control valve 304L to shift the latter from thenormal position as shown to the alternate position to automaticallypressurize the lock actuating cylinder 84 and engage the lock gear 78with the lock dog 80. Thus, when the motor M stalls when spinning uppipe joints and greater torque is needed to further turn the pipe, thesequence valve 302$, responsive to increased pressure in the motorsupply conduit will be operated to allow pressure to shift the lockcontrol valve 304L to admit pressure to the lock cylinder 84 via conduit306]. to lock or anchor the chain 12 at the motor M, so that the make upactuator cylinder MU may be operated to finally make up the pipe joint.On the other hand, if a joint is to be broken out, the main motor valveMV will be operated to drive the motor in the break out direction andthe motor may stall, without initially breaking out the pipe joint, inwhich case, the sequence valve 3028 will also be operated to admitpressure to the lock valve conduit 304 to shift the pilot operated lockvalve 3041. to the lock engaging position, in which fluid flows to thecylinder 84 via conduit 306L, and then the break out cylinder BO may beactuated to break out the joint.

The make up and break out actuators MU and B0, respectively, arecontrolled by a selector valve 3078 to which fluid is supplied via aconduit 308 from the source conduit 303.

In the position shown, the selector valve 307$ directs pressure fluidfrom the conduit to the break out cylinder conduit 309B to causeextension of the rod 135, whereby the pipe gripping means G will bemoved counter clockwise, as fluid returns to the tank from the make upactuator cylinder MU via the conduit 309M. In the alternate position, ofcourse, the pressure applied in the reverse direction will extendactuator rod 105, and fluid will be discharged back through conduit309B. Since it is desired that the usual joints be made up to aprescribed torque limit, adjustable torque limiting valve means areprovided in the pressure conduit leading to the make up actuatorcylinder MU. Thus, a normally open valve 308R is interposed between thesource of pressure and the actuator cylinder MU and is controlled by anadjustable, pressure responsive relief valve 309R which allows the valve308R to close, when pressure in line 309M exceeds a selected level. Onthe other hand to allow full torque application to the pipe whenbreaking out joints, the conduit 3098 is exposed to the full pressure ofsource conduit 303.

The system includes brake control means, as previously indicated, forthe brake means B. This control means functions to admit high pressureto the respective piston chambers 157 and 159 to force the pistons 160toward the brake disc or to reduce the pressure applied to the brakechambers 157, 159, depending upon whether more or less radial loading ofthe jaws J into gripping engagement with the pipe is necessary toprevent slipping of the gripping dies during engagement with the pipeand during spinning or make up or break out of the joint, as the casemay be.

More particularly, fluid pressure is supplied to the brake chambers 157,159 via a conduit 310 leading from the source conduit 303 under thecontrol of a normally open reducing valve 310R which is regulated by anadjustable high pressure relief valve 311R or an adjustable low pressurerelief valve 312R, depending upon the pressure of fluid in the supplyconduit 300 for the motor M. Thus, a pilot pressure conduit 313 leadsfrom the motor conduit 300 to an adjustable, normally closed reliefvalve 314R in a conduit 314 leading between the high pressure reliefvalve 311R and the low pressure relief valve 312R. When the relief valve314R is closed, as shown, fluid is supplied through the normally openvalve 310R at full source pressure from conduit 303 to apply a highbraking force, limited only by the adjustment of the relief valve 31 1R,even though the motor M is inactive. When the motor control valve MV isopened to operate the tong gripping means, the pressure in motor sourceconduit 300 will increase as the gripping means encounters resistanceupon closure of the jaws on the pipe. Since the greater the encounteredresistance, the greater the force applied by the cam ring 11 on the jawsJ to grip the pipe, the pressure in the brake chambers is preferablyreduced so that high brake force need not be overcome. The pressure inconduit 313, as it increases, will open the normally closed valve 314R,when the pressure equals the setting of the valve 314R, so that thereducing valve 310R tends to close, reducing the applied brake pressurein chambers 159. Thus, the brake control system is efiective to maintaina high brake force to assure that the pipe gripping means securely gripsthe pipe without slipping thereabout, but when the high braking force isnotneeded, the pressure is relieved. This characteristic assures longerlife of the pipe gripping dies 37 and minimized damage to the pipe dueto skidding of the dies around the pipe.

Additionally, the control system includes means for selectivelyoperating the reverse stop actuator cylinders 180, only one of which isshown in FIG. 11, for simplicity. The source conduit 303, in theillustrated system, leads to a conduit 315 which is connected to asuitable selector valve 3158. In the position shown, the valve 315$directs pressure fluid to the actuator 180 via a conduit 315M to retractthe actuator rod, and thereby position the reverse stop ring 178 in themake up position, as seen in FIGS. 5, 6, 7 and 9, and in the alternateposition of the valve 315$, pressure fluid will be supplied via aconduit 315B to shift the actuator rod to an extended position and movethe reverse stop actuator ring 178 in its alternate or break outposition of FIGS..8 and 10.

While the main control valve MV for the motor M, the make up andbreakout actuator selector valve 3078, and the reverse stop actuator selectorvalve 3158 have been herein shown, simply, as manually operated valves,it will be understood that the tong may be operated at a control consolehaving suitable means, electrical, pneumatic, or hydraulic for remotelyoperating the system or for integrating the system in an automatic welldrilling rig.

From the foregoing, it is believed that no further description of themode of operation of the present tong is necessary, and that it is nowapparent that the invention provides a novel, rugged and versatile powerpipe tong.

What is claimed is:

1. In a power pipe tong comprising: a body having an opening for a pipe,a pair of relatively rotatable members rotatably disposed in saidopening, one of said members carrying a plurality of pipe gripping jawsshiftable between retracted positions and pipe gripping positions insaid opening, the other of said members having means cooperative withsaid jaws for shifting said jaws to said pipe gripping positionsresponsive to relative rotation of said members, and drive means forrotating one of said members relative to the other to shift said jaws tosaid pipe gripping positions and for rotating said members in saidopening, said drive means including a chain engaged with said one ofsaid members, and power actuated means for driving said chain, theimprovement wherein said power actuated means comprises a rotary fluidmotor for driving said chain at high speed, and means for applying apull on a run of said chain between said motor and said one of saidmembers to further rotate said latter member when said motor is stopped.

2. In a power tong as defined in claim I, lock means for holding saidmotor against rotation when said motor is stopped.

3. In a power tong as defined in claim 1, said means for shifting saidjaws to said pipe gripping positions being operable upon relativerotation of said members in either direction.

4. In a power tong as defined in claim I, lock means for holding saidmotor against rotation when said motor is stopped, said means forshifting said jaws to said pipe gripping positions being operable uponrelative rotation of said members in either direction, means forreleasing said lock means when said motor is operating in eitherdirection and for automatically operating said lock means to hold saidmotor when said motor is stalled.

5. In a power tong as defined in claim 1, said means for shifting saidjaws to said pipe gripping positions being operable upon relativerotation of said members in either direction, said means for applying apull on a run of said chain when said motor is stopped including meansto apply said pull to either run of said chain to further rotate saidone of said members in either direction.

6. In a power tong as defined in claim 1, said means for shifting saidjaws to said pipe gripping positions being operable upon relativerotation of said members in either direction, said means for applying apull on a run of said chain when said motor is stopped including meansto apply said pull to either run of said chain to further rotate saidone of said members in either direction, and including lock means forholding said motor against rotation in either direction when said motoris stopped.

7. In a power tong as defined in claim 1, means for locking said chainbetween said motor and said meansfor applying a pull to said run of saidchain when said motor is stopped.

8. In a power tong as defined in claim 1, said means for applying a pullon a run of said chain comprising extensible pressure operated actuatorcylinder means having an idler engaged with said run of said chain.

Q. In a power operated tong as defined in claim 1, said motor and saidone of said members having chain sprockets engaged by said chain androtatable on axes disposed on a common plane, and said means forapplying a pull to a run of said chain comprising extensible fluidpressure operated cylinder means extensible in a plane parallel to theplane of the axes of said sprockets and having an idler engaging saidrun of said chain and moving said run of said chain in a loop extendingin a plane substantially parallel to said plane of the axes of saidsprockets.

10. in a power operated tong as defined in claim 1, said motor and saidone of said members having chain sprockets engaged by said chain androtatable on axes disposed on a common plane, said means for applying apull to a run of said chains comprising guide means extending in a planeparallel to the plane of said axes, a slide in said guide means, idlermeans carried by said slide and engaged with said chain, and poweractuated means for shifting said slide to pull a loop in said run ofsaid chain.

1 1. In a power tong as defined in claim 1, said means for shifting saidjaws to said pipe gripping positions being operable upon relativerotation of said members in either direction, said means for applying apull to said run of said chains including first and second poweroperated means to apply a pull to a run of said chain to move said oneof said members in either direction.

12. In a power tong as defined in claim 1, said means for shifting saidjaws to said pipe gripping positions being operable upon relativerotation of said members in either direction, said means for applying apull to said run of said chains including first and second poweroperated means to apply a pull to a run of said chain to move said oneof said members in either direction, each of said power operated meansincluding extensible pressure operated actuator cylinder means connectedat one end to said body and having at its other end an idler engagedwith a run of said chain to extend said run of said chain upon extensionof one of said actuator cylinder means.

13. ln a power tong as defined in claim 1, said means for shifting saidjaws to said pipe gripping positions being operable upon relativerotation of said members in either direction, said means for applying apull to said run of said chains including first and second poweroperated means to apply a pull to a run of said chain to move said oneof said members in either direction, each of said power operated meansincluding extensible pressure operated actuator cylinder means connectedat one end to said body and having at its other end an idler engagedwith a run of said chain to extend said run of said chain upon extensionof one of said actuator cylinder means, and means for selectivelyextending one of said actuator cylinder means.

14. In a power tong as defined in claim 1, said means for shifting saidjaws to said pipe gripping positions being operable upon relativerotation of said members in either direction, said means for applying apull to said run of said chains including first and second poweroperated means to apply a pull to a run of said chain to move said oneof said members in either direction, each of said power operated meansincluding extensible pressure operated actuator cylinder means connectedat one end to said body and having at its other end an idler engagedwith a run of said chain to extend said run of said chain upon extensionof one of said actuator cylinder means, and means for selectivelyextending one of said actuator cylinder means and allowing retraction ofthe other actuator cylinder means.

15. In a power tong as defined in claim 1, said means for shifting saidjaws to said pipe gripping positions being operable upon relativerotation of said members in either direction, said means for applying apull to said run of said chains including first and second poweroperated means to apply a pull to a run of said chain to move said oneof said members in either direction, each of said power operated meansincluding extensible pressure operated actuator cylinder means connectedat one end to said body and having at tis other end an idler engagedwith a run of said chain to extend said run of said chain upon extensionof one of said actuator cylinder means, and including guide means forsaid idler of each of said actuator cylinder means for guiding saididlers along planes parallel to the plane of the axis of rotation ofsaid one of said members to pull a loop in said chain.

16. In a power tong as defined in claim l, lock means for holding saidmotor against rotation when said motor is stopped, said lock meanscomprising a lock dog, said motor having a shaft having a lock gearthereon, and means for actuating said dog into and from engagement withsaid lock gear.

17. In a power tong as defined in claim I, lock means for holding saidmotor against rotation when said motor is stopped, said lock meansincluding a lock member shiftable between a motor locking position and areleased position, and actuator means for shifting said lock member.

18. In a power tong as defined in claim I, lock means for holding saidmotor against rotation when said motor is stopped, said lock meansincluding a lock member shiftable between a motor locking position and areleased position, and actuator means for shifting said lock memberautomatically between said positions to lock said motor when said motorapplies a selected torque to said rotatable members.

19. In a power tong as defined in claim 1, lock means for holding saidmotor against rotation when said motor is stopped, said lock meansincluding a lock member shiftable between a motor locking position and areleased position, and actuator means for shifting said lock memberautomatically between said positions to lock said motor when said motorapplies a selected torque to said rotatable members, said means forshifting said jaws to said pipe gripping positions being operable uponrelative rotation of said members in either direction, said means forapplying a pull to said run of said chains including first and secondpower operated means to apply a pull to a run of said chain to move saidone of said members in either direction.

20. In a power tong as defined in claim I, lock means for holding saidmotor against rotation when said motor is stopped, said lock meansincluding a lock member shiftable between a motor locking position and areleased position, and actuator means for shifting said lock memberautomatically between said positions to lock said motor when said motorapplies a selected torque to said rotatable members, said means forshifting said jaws to said pipe gripping positions being operable uponrelative rotation of said members in either direction, said means forapplying a pull to said run of said chains including first and secondpower operated means to apply a pull to a run of said chain to move saidone of said members in either direction including extensible pressureoperated actuator cylinder means, and means for selectively supplyingpressure fluid to said cylinder means.

@ 5 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N 3 975 Dated September 19, 1972 Inventor(s) BELA GECZY ET AL It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Col. 3, line 43, "as" should be a--. C01. i, line "Break" shouId be--Brake-. line 1 "to" should be -the-- line 15, "for" should be.--'-the--. e line 1?, "Break" should be --Brake--.' H Col. 5, line 2'9,"the", second occurrence, should be "and";

same line, "set" should be "seat- Col. 6, line 51; "conduit" should be--conduct--. Col. 7., line 7, 'I'oller" should be -rollers--. Col. line56, "extend" should be -'--extent--. Col. 9, line 36, after "fluid"insert -is-. line 554, "sequency" should .be -sequence--. Col. 11, line29, "minimized" should be --'minimizes- Signed and sealed this- 15th dayof May 1973.

(SEAL) Aetest:

EDWARD M.FLETCHER,J R. I ROBERT GOTTSCHALK Attesting OfficerCommissioner of Patents

1. In a power pipe tong comprising: a body having an opening for a pipe,a pair of relatively rotatable members rotatably disposed in saidopening, one of said members carrying a plurality of pipe gripping jawsshiftable between retracted positions and pipe gripping positions insaid opening, the other of said members having means cooperative withsaid jaws for shifting said jaws to said pipe gripping positionsresponsive to relative rotation of said members, and drive means forrotating one of said members relative to the other to shift said jaws tosaid pipe gripping positions and for rotating said members in saidopening, said drive means including a chain engaged with said one ofsaid members, and power actuated means for driving said chain, theimprovement wherein said power actuated means comprises a rotary fluidmotor for driving said chain at high speed, and means for applying apull on a run of said chain between said motor and said one of saidmembers to further rotate said latter member when said motor is stopped.2. In a power tong as defined in claim 1, lock means for holding saidmotor against rotation when said motor is stopped.
 3. In a power tong asdefined in claim 1, said means for shifting said jaws to said pipegripping positions being operable upon relative rotation of said membersin either direction.
 4. In a power tong as defined in claim 1, lockmeans for holding said motor against rotation when said motor isstopped, said means for shifting said jaws to said pipe grippingpositions being operaBle upon relative rotation of said members ineither direction, means for releasing said lock means when said motor isoperating in either direction and for automatically operating said lockmeans to hold said motor when said motor is stalled.
 5. In a power tongas defined in claim 1, said means for shifting said jaws to said pipegripping positions being operable upon relative rotation of said membersin either direction, said means for applying a pull on a run of saidchain when said motor is stopped including means to apply said pull toeither run of said chain to further rotate said one of said members ineither direction.
 6. In a power tong as defined in claim 1, said meansfor shifting said jaws to said pipe gripping positions being operableupon relative rotation of said members in either direction, said meansfor applying a pull on a run of said chain when said motor is stoppedincluding means to apply said pull to either run of said chain tofurther rotate said one of said members in either direction, andincluding lock means for holding said motor against rotation in eitherdirection when said motor is stopped.
 7. In a power tong as defined inclaim 1, means for locking said chain between said motor and said meansfor applying a pull to said run of said chain when said motor isstopped.
 8. In a power tong as defined in claim 1, said means forapplying a pull on a run of said chain comprising extensible pressureoperated actuator cylinder means having an idler engaged with said runof said chain.
 9. In a power operated tong as defined in claim 1, saidmotor and said one of said members having chain sprockets engaged bysaid chain and rotatable on axes disposed on a common plane, and saidmeans for applying a pull to a run of said chain comprising extensiblefluid pressure operated cylinder means extensible in a plane parallel tothe plane of the axes of said sprockets and having an idler engagingsaid run of said chain and moving said run of said chain in a loopextending in a plane substantially parallel to said plane of the axes ofsaid sprockets.
 10. In a power operated tong as defined in claim 1, saidmotor and said one of said members having chain sprockets engaged bysaid chain and rotatable on axes disposed on a common plane, said meansfor applying a pull to a run of said chains comprising guide meansextending in a plane parallel to the plane of said axes, a slide in saidguide means, idler means carried by said slide and engaged with saidchain, and power actuated means for shifting said slide to pull a loopin said run of said chain.
 11. In a power tong as defined in claim 1,said means for shifting said jaws to said pipe gripping positions beingoperable upon relative rotation of said members in either direction,said means for applying a pull to said run of said chains includingfirst and second power operated means to apply a pull to a run of saidchain to move said one of said members in either direction.
 12. In apower tong as defined in claim 1, said means for shifting said jaws tosaid pipe gripping positions being operable upon relative rotation ofsaid members in either direction, said means for applying a pull to saidrun of said chains including first and second power operated means toapply a pull to a run of said chain to move said one of said members ineither direction, each of said power operated means including extensiblepressure operated actuator cylinder means connected at one end to saidbody and having at its other end an idler engaged with a run of saidchain to extend said run of said chain upon extension of one of saidactuator cylinder means.
 13. In a power tong as defined in claim 1, saidmeans for shifting said jaws to said pipe gripping positions beingoperable upon relative rotation of said members in either direction,said means for applying a pull to said run of said chains includingfirst and second power operated means to apply a pull to a run of saidchain to move said one of said members in eiTher direction, each of saidpower operated means including extensible pressure operated actuatorcylinder means connected at one end to said body and having at its otherend an idler engaged with a run of said chain to extend said run of saidchain upon extension of one of said actuator cylinder means, and meansfor selectively extending one of said actuator cylinder means.
 14. In apower tong as defined in claim 1, said means for shifting said jaws tosaid pipe gripping positions being operable upon relative rotation ofsaid members in either direction, said means for applying a pull to saidrun of said chains including first and second power operated means toapply a pull to a run of said chain to move said one of said members ineither direction, each of said power operated means including extensiblepressure operated actuator cylinder means connected at one end to saidbody and having at its other end an idler engaged with a run of saidchain to extend said run of said chain upon extension of one of saidactuator cylinder means, and means for selectively extending one of saidactuator cylinder means and allowing retraction of the other actuatorcylinder means.
 15. In a power tong as defined in claim 1, said meansfor shifting said jaws to said pipe gripping positions being operableupon relative rotation of said members in either direction, said meansfor applying a pull to said run of said chains including first andsecond power operated means to apply a pull to a run of said chain tomove said one of said members in either direction, each of said poweroperated means including extensible pressure operated actuator cylindermeans connected at one end to said body and having at tis other end anidler engaged with a run of said chain to extend said run of said chainupon extension of one of said actuator cylinder means, and includingguide means for said idler of each of said actuator cylinder means forguiding said idlers along planes parallel to the plane of the axis ofrotation of said one of said members to pull a loop in said chain. 16.In a power tong as defined in claim 1, lock means for holding said motoragainst rotation when said motor is stopped, said lock means comprisinga lock dog, said motor having a shaft having a lock gear thereon, andmeans for actuating said dog into and from engagement with said lockgear.
 17. In a power tong as defined in claim 1, lock means for holdingsaid motor against rotation when said motor is stopped, said lock meansincluding a lock member shiftable between a motor locking position and areleased position, and actuator means for shifting said lock member. 18.In a power tong as defined in claim 1, lock means for holding said motoragainst rotation when said motor is stopped, said lock means including alock member shiftable between a motor locking position and a releasedposition, and actuator means for shifting said lock member automaticallybetween said positions to lock said motor when said motor applies aselected torque to said rotatable members.
 19. In a power tong asdefined in claim 1, lock means for holding said motor against rotationwhen said motor is stopped, said lock means including a lock membershiftable between a motor locking position and a released position, andactuator means for shifting said lock member automatically between saidpositions to lock said motor when said motor applies a selected torqueto said rotatable members, said means for shifting said jaws to saidpipe gripping positions being operable upon relative rotation of saidmembers in either direction, said means for applying a pull to said runof said chains including first and second power operated means to applya pull to a run of said chain to move said one of said members in eitherdirection.
 20. In a power tong as defined in claim 1, lock means forholding said motor against rotation when said motor is stopped, saidlock means including a lock member shiftable between a motor lockingposition and a released position, and actuator means for shifting saidlock member automatically between said positions to lock said motor whensaid motor applies a selected torque to said rotatable members, saidmeans for shifting said jaws to said pipe gripping positions beingoperable upon relative rotation of said members in either direction,said means for applying a pull to said run of said chains includingfirst and second power operated means to apply a pull to a run of saidchain to move said one of said members in either direction includingextensible pressure operated actuator cylinder means, and means forselectively supplying pressure fluid to said cylinder means.